1. Field of the Invention
The present invention relates to a bidirectional remote control unit capable of bidirectionally communicating with a display apparatus, such as a television set.
2. Description of the Related Art
A conventional bidirectional remote control unit is configured to be capable of shifting information concerning operations to be performed on the screen of a television set onto a display device of the bidirectional remote control unit itself, for execution of the operations thereon, whereby a viewer's convenience is improved to enhance the commercial value of the television set.
Further, there has been proposed a bidirectional remote control unit for operating a video apparatus, which is capable of displaying reproduction information on a recorded magnetic tape in the video apparatus, and which includes a changeover switch for selecting between display and non-display of images (see, e.g., Japanese Laid-Open patent Publication (Kokai) No. 2001-103334).
A bidirectional remote control unit of the above-mentioned type is provided with a built-in secondary battery as a power supply.
However, in the conventional bidirectional remote control unit, the capacity of the secondary battery is small relative to the power consumption of the bidirectional remote control unit, and hence the voltage of the secondary battery tends to soon become lower than a predetermined level. To eliminate this inconvenience, a bidirectional remote control unit capable of controlling the power consumption thereof is currently demanded. The above-mentioned problem occurs not only when a secondary battery is used, but also when a primary battery, which is unrechargeable, is used.
Further, a video image is sent from the controlled apparatus to the bidirectional remote control unit by wireless transmission using infrared rays, and hence when the state of transmission become worse, the error rate of the video image increases, which causes disturbance of the video image displayed on the remote control unit. Furthermore, if reception sensitivity is enhanced so as to improve the transmission state at all, the power consumption of the bidirectional remote control unit increases. Therefore, there is currently a demand for a bidirectional remote control unit capable of controlling the power consumption thereof by taking the state of transmission into consideration.